Papilloedema is a non-inflammatory congestion of the optic disc, invariably associated with raised intracranial pressure. It is most often bilateral. General features reflect the underlying disease process but a choked disc is characteristic although differentiation from papillitis may be difficult.
Vision is rarely affected in acute papilloedema but peripheral vision may be lost in chronic cases where it is frequently accompanied by transient visual obscurations.
Papilloedema will not occur in the presence of optic atrophy as in the Foster-Kennedy syndrome where there is unilateral optic atrophy and contralateral papilloedema, or if the optic nerve sheath on that side is not patent.